Can anyone help me in doing Orthorcetification in ENVI? I am trying to orthorectify IKONOS image. I downloaded both ASTER DEM and SRTM for the orthorectification, and then changed the projection of IKONOS image from JGD2000 to UTM ( this image was taken in Japan) by ENVI to adapt with the projection of ASTER or SRTM. However, after filling all of the necessary parameters in the Orthorectification Parameter table, I could not process the image due to an error: "Problem: Image and DEM do not overlap" (happened for both cases of using ASTERDEM and SRTM). I am looking forward to see your respond. Thank you very much in advance.